This document displays the different options to geolocate the images such that the geolocation can be imported into PIX4Dmapper. It also shows the impact of the different methods on the different actors of the software (Pix4D, User, Partner)
There are different ways to geolocate the images:
1. EXIF (exif)
2. Generate .p4d using a minimum p4d format (xml)
3. Pix4D geolocation CSV file (csv)
4. Generate .p4d using the command line (cmd)
5. Parse a flight log (log parser)
The following table sums up which options are recommended.
The image geolocation can be loaded from standard EXIF tags if they are stored there. Only image positions in WGS84 can be read from the EXIF.
The implications for the different software actors are the following:
- Pix4D: Image geolocation is automatically imported from the EXIF tags when importing the images. Nothing more needs to be implemented.
- User: Image geolocation automatically imported when adding the images to the project.
- Partner: Needs to write the image geolocation in the right EXIF tags. Needs to implement the appropriate synchronization between images and GPS positions.
For a list of EXIF tags read by Pix4Dmapper: EXIF and XMP tag information read by Pix4D.
Generate .p4d using a minimum p4d format (xml)
The .p4d project file contains information about the project such as images, coordinate systems, GCPs, processing options, etc. The .p4d file is in XML format and has a formal definition by means of a XSD (XML Schema Document) file. The missing information will be automatically written by the software when reading the .p4d file. The missing information will correspond to the default project parameters.
The implications for the different software actors are the following:
- Pix4D: The file format might change and not be compatible anymore for newer versions.
- User: The project file can directly be opened in Pix4Dmapper. Nothing else needs to be done by the user.
- Partner: Needs to create the .p4d file using the correct format. The file format might change and not be compatible anymore for newer versions. Can already set some processing options which facilitate the integration with Pix4Dmapper. Can cover more cases than with the command line (e.g. in the command line the image geolocation can be imported only if it is in WGS84)
For more information on the minimum p4d format: .p4d minimum format.
Pix4D geolocation CSV file (csv)
The image geolocation can be imported from a .csv, .txt or .dat file. Each line contains the geolocation for one image. Each value on a line is separated by a comma.
The implications for the different software actors are the following:
- Pix4D: The image geolocation is automatically loaded from the geolocation file. Nothing more needs to be implemented.
- User: Needs to have an image geolocation file in the right format, either done by himself or provided by the acquisition system used. Needs to import the file to geolocate the images.
- Partner: Needs to provide the geolocation file in the right format. Needs to implement the appropriate synchronization between images and GPS positions.
For more information about the Pix4D geolocation file format: Input files.
Generate .p4d using the command line (cmd)
The .p4d project file can be generated using the command line to create a new project. It implies that the image geolocation is either written in the EXIF or loaded from a .csv file. The geolocation has to be in WGS84.
The implications for the different software actors are the following:
- Pix4D: The project file has the right format.
- User: The project file can directly be opened in Pix4Dmapper. Nothing else needs to be done by the user.
- Partner: Needs to write the image geolocation in the right EXIF tags or to create a geolocation CSV file in the right format. Needs to implement the appropriate synchronization between images and GPS positions. Needs to generate the .p4d file using the command line which implies the installation of PIX4Dmapper. Can already set some processing options which facilitate the integration with PIX4Dmapper.
For more information about the command line: How to use the command line.
Parse a flight log (log parser)
The flight log of a given partner is parsed by PIX4Dmapper.
The implications for the different software actors are the following:
- Pix4D: Needs to parse the flight log and to implement the appropriate synchronization between images and GPS positions. Needs to maintain the parsing if the log format changes.
- User: Needs to import the flight log after importing the images in order to geolocate them.
- Partner: Does not need to do anything. Needs to communicate to Pix4D how to parse the flight log and when the flight log format changes.